An intersubband electroluminescent light source in the 8–13 &mgr;m spectral region is reported. The structure was grown by molecular beam epitaxy in the lattice matched AlInAs/GaInAs material system and consists of coupled‐quantum‐well active regions alternated with compositionally graded electron injecting regions. The device operates in the temperature range from 10 to 200 K with measured integrated optical powers up to 6 nW. The peak of the electroluminescent spectrum blue shifts linearly with current due to the Stark effect. From these data and straightforward electrostatic considerations we obtain the intersubband nonradiative electron lifetime, in good agreement with the calculations. ©1995 American Institute of Physics.